U.S. patent number 4,210,976 [Application Number 05/908,246] was granted by the patent office on 1980-07-08 for arrangement for removing the slag incrustations on melting and casting vessels.
This patent grant is currently assigned to Otto Junker GmbH. Invention is credited to Heinz Apelt, Helmut Packes.
United States Patent |
4,210,976 |
Apelt , et al. |
July 8, 1980 |
Arrangement for removing the slag incrustations on melting and
casting vessels
Abstract
The device for removing incrustations from the inner wall of a
cylindrical vessel comprises a driven shaft supported for rotation
in the vessel about its central axis and for a vertical movement
along this axis. Impact tools, preferably in the form of prismatic
blocks defining a straight edge, are attached respectively to the
shaft by a pair of chains in such a manner that the abrading edge
of each tool extends parallel to the central axis when the chains
are straightened by the centrifugal force.
Inventors: |
Apelt; Heinz (Roetgen,
DE), Packes; Helmut (Kettenis, BE) |
Assignee: |
Otto Junker GmbH (Simmerath,
DE)
|
Family
ID: |
6009801 |
Appl.
No.: |
05/908,246 |
Filed: |
May 22, 1978 |
Foreign Application Priority Data
|
|
|
|
|
May 25, 1977 [DE] |
|
|
2723547 |
|
Current U.S.
Class: |
15/246.5;
15/104.096 |
Current CPC
Class: |
F27D
25/001 (20130101); F23J 3/02 (20130101); F27B
14/08 (20130101) |
Current International
Class: |
F27D
23/00 (20060101); F27D 23/02 (20060101); F27B
14/00 (20060101); F27B 14/08 (20060101); B08B
001/04 () |
Field of
Search: |
;134/8
;15/93R,93A,246.5,14.1C ;266/135 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Fisher; Richard V.
Attorney, Agent or Firm: Striker; Michael J.
Claims
What is claimed as new and desired to be protected by Letters
Patent is set forth in the apended claims:
1. A device for removing incrustations from the inner wall surface
of a cylindrical vessel defining a central axis, comprising a
driven body; means for mounting said body on a vessel so that said
body rotates about said axis and is movable lengthwise of the same
while being prevented from movement transversely of said axis; a
plurality of impact tools spaced circumferentially about said body
and each having a straight abrading edge adjacent the inner wall
surface and a face directed towards said axis; and a pair of
axially spaced flexible links of identical radial length for each
of said impact tools and having inner ends connected to said body
and outer ends connected to the respective face at locations
thereof which are spaced lengthwise of said axis, such that the
abrading edge of each impact tool is held along the inner
circumference of the vessel lining in an operating position in
which it extends approximately parallel to said axis during
rotation of said body and beyond which it cannot approach the
vessel lining in radial direction, so that the tool can remove
deposits from the vessel lining but cannot damage the vessel lining
itself.
2. The device as defined in claim 1, wherein said pairs of links
with the assigned tools are regularly arranged in radial planes
about the periphery of said body.
3. The device as defined in claim 1, wherein said impact tools are
metallic blocks.
4. The device as defined in claim 3, wherein said blocks are
rectangular prisms.
5. The device as defined in claim 1, wherein said links have
adjustable length to delimit a desired radial range of attack of
said tools against the lining of said vessel.
6. The device as defined in claim 1, wherein said flexible links
are chains.
7. The device as defined in claim 1 further including a stationary
carrier frame, vertically adjustable supporting means arranged on
said carrier frame, a driving assembly including a driving shaft
supported for rotation about said central axis on said adjustable
supporting means and being connected at its free end to said driven
body.
8. The device as defined in claim 7, wherein said vertically
adjustable supporting means includes a sliding guide, a bearing
bracket for said shaft movably supported in said guide and a
hydraulic cylinder piston unit for vertically adjusting said
bearing bracket.
9. The device as defined in claim 8, further including a driving
motor arranged on said bearing bracket, and transmission gears
between said driving motor and said driving shaft.
10. A device for removing incrustations from the inner wall of a
cylindrical vessel defining a central axis, comprising: a driven
body supported for rotation in said vessel about said axis and for
vertical movement along said axis, said driven body being assembled
of two discs arranged at a distance one above the other, a
plurality of bearing sleeves uniformly arranged around the
periphery of said discs and supported for rotation about respective
axes parallel to said central axis, and outwardly extending arms
secured to respective sleeves in a radial plane; a plurality of
pairs of flexible links, the links of each pair being arranged in
axial direction one above the other and being secured at one end
thereof to the free ends of said arms; and a plurality of impact
tools defining a straight abrading edge and being secured at points
opposite said edge to the other ends of said pairs of links, such
that the abrading edge of each impact tool is held along the inner
circumference of the vessel lining in an operating position at
least approximately parallel to the central axis during rotation of
the body.
11. The device as defined in claim 10, wherein said arms are bent
in the radial plane against the direction of rotation of said
body.
12. The device as defined in claim 10, wherein said arms are
vertically offset relative to each other.
13. The device as defined in claim 10 further including arresting
means for arresting said arms in a predetermined angular position
in said radial plane.
14. The device as defined in claim 13, further including an
adjusting device for adjusting said angular position of said arms,
said adjusting device including sprocket wheels supported for joint
rotation on said bearing sleeve, an endless chain coupling said
sprocket wheels, and an arrestable drive gear engaging said endless
chain to adjust the angular position of said sprocket wheels.
15. The device as defined in claim 14, wherein said driven body is
connected to a hollow driving shaft and further including adjusting
linkage for controlling said adjusting device of said carrier arms,
said adjusting linkage passing through said hollow shaft and
cooperating with said arresting means.
16. The device as defined in claim 15, wherein said arresting means
include a lever secured to the upper end of said adjustment linkage
and stop members arranged on a bracket and cooperating with said
lever to limit the angular position of said linkage.
17. The device as defined in claim 16, wherein said adjustment
linkage includes a tooth wheel connected to the lower end of said
adjustment linkage and coupled to said endless chain to adjust the
angular position of said arms.
Description
BACKGROUND OF THE INVENTION
The invention relates to a method and an arrangement for removing
the slag incrustations as well as possibly also the inner marginal
layers infiltrated by metal or metal oxides, on the refractory
inner lining, particularly ceramic lining, of melting or casting
vessels which are at least internally cylindrical over the
substantial part of their length.
During the operative use of such vessels, slag deposits on the
internal walls of the lining which come into contact with the
molten material. Not only can these slag incrustations become so
thick that they considerably reduce the volumetric capacity of the
vessels, but also they cause, and especially in induction heated
vessels, a considerable reduction in the melting output so that the
manufacturing operation is sensibly interfered with. Therefore, it
is necessary to remove these slag incrustations from time to
time.
These operations are performed predominantly manually, using
special tools and requiring heavy physical exertion on the part of
the operating personnel. Herein, such operations are preferably
carried out with the vessel in hot condition inasmuch as the slag
incrustations can be more readily removed under these conditions.
However, the worker discomfort due to the heat is very great when
resort is had to this operating procedure. While it is true that
the removal of the incrustations is more difficult in the cold
state of the vessels, the discomfort resulting from the heat which
is radiated from the vessel interior is avoided under these
conditions. Whether operations are carried out in the cold or in
the hot condition of the vessel, however, the wear of the cleaning
tools which have been heretofore used for this purpose is very
high.
It would be conceivable to perform the removal of the slag
incrustations mechanically by drilling or boring as it is known,
for instance, for the renewal of the refractory lining in melting
vessels. However, even disregarding the fact that the wear of the
drilling tools is very high even here because of the extremely hard
and brittle slag incrustations, a special problem exists here which
resides in the fact that the slag incrustations or deposits do not
have any uniform thickness, but rather that this thickness
considerably varies both in the circumferential direction of the
vessels as well as over their internal height. When it is desired
not to run the danger that the drilling tools which, for the most
part, also consist of a brittle material, would break due to too
high impact stressing, it is necessary, in a very expensive and
time-consuming manner, to begin with the smallest possible boring
radius and to gradually increase the same in the course of several
passes.
Because of the high machinery, time or labor expenditure and the
high susceptibility of the boring apparatus to malfunction, which
are encountered when the above approach is taken, all attempts to
remove the slag incrustations in this manner have failed in the
practice so that it remained by the, however also laborious, manual
removal of the slag incrustations by means of special tools.
On top of this, what is common to both of these methods is that the
danger exists to a high degree that, during the removal of the slag
incrustations as well as the possible erosion of the inner marginal
layers of the ceramic inner lining which have been infiltrated by
metal or metallic oxides, even the unused lining material as well
as, under certain circumstances, even the vessel masonry itself,
are damaged.
SUMMARY OF THE INVENTION
It constitutes a task of the invention to provide a method and an
arrangement which render it possible to remove the slag
incrustations as well as possibly also the inner marginal layers of
the inner lining of melting or casting vessels of the initially
described type, which have been infiltrated by metal or metallic
oxides, while by using machinery, still in a substantially shorter
period of time, more efficiently and also simultaneously in a more
sparing manner.
To solve this problem, the method of the invention is characterized
in that the slag incrustations or infiltrated marginal layers are
abraded by means of tools which hit and scrape the same, utilizing
tangential rotary impulses. Preferably, this occurs in such a
manner that the removal of the slag incrustations and infiltrated
marginal layers is achieved by means of abrading tools which rotate
in the interior of the vessel and which simultaneously are
longitudinally moved, either in a continuous or in a stepwise
manner, in the axial direction of the vessel, being radially as
well as tangentially flexibly guided and, consequently, acting on
the internal wall of the lining by radial and tangential
impact.
It has been surprisingly established that, in this manner, it is
possible to so fully and uniformly remove even very differently
thick and, additionally, extremely hard and brittle slag
incrustations, usually in only one vertical traverse and in a very
short period of time, that cumbersome aftertreatments by hand can
be avoided. This is true not only for the removal of the slag
incrustations, but also for the abrasion of the inner marginal
layers of the lining which have been infiltrated by metal or
metallic oxides, and this without having to fear that the still
sound lining material would suffer damage, or break out.
As a result of the fact that the abrading tools are flexibly
guided, both radially as well as tangentially, they can act during
their orbiting movement along the inner circumference of the lining
on the rigid incrustations, especially on thick and hard
incrustations, with a high kinetic energy indeed correspondingly to
their high tangential rotary impulse, but they also partially give
way and remove the same only gradually in the course of the
following orbiting movements, in this manner. This operating
procedure has the considerable advantage, especially as compared to
the boring of the slag incrustations, that the abrading tools, on
the one hand, cannot seize and that they, on the other hand, spare
the vessel wall. Break-outs, cracks or the like did not occur or
have not been observed during the use of the method acccording to
the invention.
A further advantage of the method according to the invention
resides in that that not only the slag incrustations, but also the
inner marginal layers of the lining which have been, to a greater
or lesser degree, infiltrated with metal or metallic oxides, can be
abraded in a uniform manner and in the single vertical traverse,
without destroying or impairing still intact regions of the lining
which are situated behind these marginal layers.
The invention is primarily based on the recognition of the fact
that the abrading tools, which rotate in the vessel interior and
which are radially as well as tangentially flexibly guided, operate
the more efficiently the harder and more brittle the slag
incrustations or the inner marginal layers of the lining which are
infiltrated with metal or metallic oxides are and that, on the
other hand, the still intact lining material which is softer as
compared to the slag, is spared.
A further significant advantage of the method of the invention
resides in the fact that the radial operating region of the
radially as well as tangentially guided flexible abrading tools can
be pre-determined or adjusted, partially in dependence on the speed
of rotation and partially in dependence on the limitation of their
radial flexibility, in such a manner that it is possible, with
respect to a predetermined inner vessel diameter, to leave them, by
and large, to themselves independently on the thickness and
irregularity of the inner slag incrustations. While they, to a
certain extent, "trail" when the slag incrustations are thick at
the beginning of the eroding operation, in the direction of
rotation or tangentially to the direction of rotation, and perform
the more effective hitting work, the predetermined limitation of
their radial flexibility, possibly in connection with a
corresponding increase in the speed of rotation, automatically
results in that they, owing to the centrifugal forces, change from
the initially predominantly striking to a more scraping mode of
operation with the increasing degree of abrasion and finally, after
the substantial abrasion even of the inner marginal layers of the
lining which have been infiltrated with metal or metal oxides, they
work only in a grinding mode of operation. A damage to, or even
destruction of the still intact regions of the lining lying behind
the same is securely avoided in this manner, and it is
simultaneously assured that the inner surface of the remaining
lining will come out completely smooth and concentric. The abraded
layer, as a result of this, can be easily and unproblematically
replaced, in a conventional manner, by a coating of a fresh ceramic
material, without running into additional and cumbersome repair
operations prior to the same.
While it is often advantageous to operate at a lower speed of
rotation at the beginning of the abrading operation in dependence
on the centrifugal mass of the abrading tools, it is recommended to
gradually increase the same, preferably in a stepless manner. At a
centrifugal mass of the abrading tools in the order of magnitude of
upto approximately 20 kg, it has been established to be
advantageous to operate at a speed of orbiting amounting to at
least approximately 4 m/sec, however, at most upto approximately 15
m/sec, wherein the suitable selection of the speed of rotation as
well as of the centrifugal mass of the abrading tools depends,
however, to a great degree, on the character or the rigidity and
brittleness of the slag incrustations as well as of the infiltrated
marginal layers, so that they can possibly be empirically
optimized.
The abrading tools are simultaneously moved, during their orbiting
motion, relative to the inner wall of the vessel parallel to its
longitudinal axis at a speed which is relatively low in comparison
to the orbiting motion, being between approximately 0.01 and 0.5
m/sec. Under these circumstances, it is sufficient, as a rule, to
let the abrading tools pass through the vessel interior and over
its height, only once from below to above, and it is not necessary
to repeat this traverse in the opposite direction of movement.
It has further been proved to be advantageous to perform the
abrasion of the slag incrustations and infiltrated marginal layers
on the hot internal wall of the vessel lining, for which the
vessel, or at least the internal wall of the vessel lining, must
possibly be heated during the abrading operation. It has been found
to be advantageous to maintain the vessel lining, during the
abrading operation, depending on the composition of the slag and/or
the type of metals or metallic oxides infitrated into the inner
marginal layers--possibly by afterheating or additional heating--at
a temperature between approximately 300.degree. and 1400.degree.
C., preferably between 600.degree. and 1200.degree. C. In this
manner, the time needed for the abrading operation can be
significantly shortened and, on the other hand, the wear-dependent
durability of the abrading tools can be increased to a not
insignificant degree. While the low temperature values are
contemplated mainly for vessels for light-metal melts, such as, for
instance, aluminum or aluminum alloys, the higher temperature
values are meant more for vessels for iron-metal or steel
melts.
A device for performing the method includes, in accordance with the
invention, a driven rotary body which is centrally introducible
into the vessel and the radial position of which relative to the
same is fixed by its bearing means. The vertical position of the
body is adjustable along the central axis of the vessel and over
the height of the internal wall. The body is provided with a
plurality of abrading tools that are uniformly arranged about its
periphery and are secured thereto for a limited movement in radial
and tangential directions by flexible links.
The abrading tools advantageously consist of blocks, preferably of
metal, which are elongated in direction parallel to the central
axis and are configurated with edges at least at their longitudinal
side which faces the internal lining of the vessel. According to a
preferred further development, the abrading tools consist of
substantially prismatically configurated steel blocks having
rectangular or square cross-sectional shape.
These eroding tools are connected with the rotary body flexibly at
least in the radial plane and the flexible connecting means have a
length which delimits the predetermined radial range of attack of
the abrading tools on the internal wall.
The connecting means between the rotary body and the abrading tools
can include, for example, leaf springs, but they are preferably
constructed as chains, especially in the form of link or side-bar
chains. Herein, an especially preferred further development resides
in that the abrading tools are respectively connected to the rotary
body by means of at least two chains arranged at an axial distance
from one another, that they hold the abrading edge of the tools
during their orbiting or rotational movement along the inner
circumference of the vessel lining in an operating position
approximately parallel to the central vessel axis.
The rotationally symmetrical rotary body is configurated
substantially to a disk shape in the plane transverse to the
central axis of the vessel and is provided at its outer periphery,
symmetrically distributed over the same, with at least three
abrading tools hanging thereon with the interposition of the
flexible connecting means.
In a simple embodiment, the rotary body is shaped as a rotary
cross. In order to be able to fit the arrangement to vessels having
different inner diameters, it is advantageous to make the arms of
the rotary cross adjustable, for instance telescopically, whereby
the flexible connecting means for the abrasion tools are affixed to
their free ends.
According to another preferred further development of the
invention, the rotary body consists of two disks which are arranged
at a distance one above the other and between which there are
mounted, uniformly distributed over the periphery, for pivoting in
the radial plane, by means of bearing sleeves, outwardly pointing
carrier arms which are provided at their outer ends with the
flexible connecting means for the connection of the abrading tools.
The carrier arms can be curved or angled at least in the radial
plane counter the direction of rotation and possibly also be
vertically offset with respect to one another. The latter
arrangement is recommended especially when the rotary body has,
distributed over its periphery, more than 4, for instance, 6 or 8,
carrier arms for the abrading tools, in order to increase the
productivity of the arrangement in this manner.
An adjustment of the carrier arms for varying or fitting the range
of the radial attack of the abrading tools hanging on them is also
possible and advantageous even in this exemplary embodiment. This
is achieved, for instance, advantageously in that the carrier arms
are tiltable out of their substantially radial normal position,
preferably against the direction of rotation and are arrestable in
their respective tilted position.
In order to be able to jointly and uniformly adjust all of the
carrier arms by means of a shared adjusting arrangement, it is
advantageous in accordance with an expedient further development of
the invention, to provide an adjusting arrangement which consists,
on the one hand, of an endless chain which couples sprocket wheels,
which are rotationally associated with the bearing sleeves of the
carrier arms, with one another in the rotating sense and, on the
other hand, of a further toothed wheel which is connected with an
arrestable adjustment drive and is at least mediately coupled with
the endless chain in the rotating sense.
The rotary body which carries the abrading tools may be suspended,
in a simple manner, by means of a driving shaft that is coaxial
with the central vessel axis, from a carrier frame which is
supported either on the edge of the vessel itself or, by means of a
scaffolding, on the floor next to the vessel, while means for the
vertical adjustment of the bearing as well as for the rotary drive
of the driving shaft are supported on the carrier frame.
The means for the vertical adjustment of the bearing of the driving
shaft can consist, for example, of a spindle drive immediately
cooperating with the driving shaft or--preferably--of a hydraulic
cylinder-and-piston unit by means of which the bearing bracket
which carries the driving shaft is shiftable within a vertical
sliding guide of the carrier frame. Under the circumstances, this
can be accomplished also by means of the available hall crane.
The driving aggregate for the rotary drive of the driving shaft is
preferably constituted by a steplessly controllable motor,
particularly a compressed air motor, the pinion of which
advantageously directly meshes with a gear ring of the driving
shaft.
In this connection, an especially advantageous form of an
embodiment results when the driving shaft for the rotary body is
configurated as a hollow shaft which accommodates in its axial
center the adjusting linkage for the adjustment drive of the
carrier arms that are tiltable in the radial plane. Then, the
adjustment linkage that axially passes through the hollow driving
shaft is provided, at the upper end, outwardly of the driving
shaft, with a tilting lever which is arrestable in its respective
position by means of detents, abutments or the like which rotate
together with the driving shaft. Then, expediently, the adjustment
linkage carries at its lower end the toothed wheel for the common
adjustment of all of the carrier arms. The adjustment is effected
by means of an endless chain which is also in engagement with a
further toothed wheel of one of the bearing sleeves of the carrier
arms.
In the following, two preferred embodiments of the invention are
described in connection with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an embodiment of the device of this invention during the
operation in a melting vessel, shown in a perspective, partially
sectioned view;
FIG. 2 is a fragmentary and longitudinally sectional view of a
melting vessel with a further embodiment of the device of this
invention;
FIG. 3 is the device according to FIG. 2 during use in a melting
vessel of a smaller diameter and
FIG. 4 is a diagrammatic longitudinal section of the of the melting
vessel with the embodiment of the device according to FIGS. 2 and
3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, the crucible-shaped melting vessel, which can be heated
in a non-illustrated manner, is indicated with 1. It consists of a
metallic outer wall 2 and a ceramic lining 3 which adjoins the same
inwardly and which is burdened after a longer use in the melting
and casting operation at the internal wall 3a with slag
incrustations 4. Additionally, the inner marginal layers of the
lining, which are infiltrated by metal or metallic oxides, are
indicated by 4a.
The melting vessel 1 is provided at its upper edge region with a
walking operating platform 5a for the operating personnel.
At the level of the upper edge of vessel 1, a metallic frame 5 is
attached at the outer wall 2, which serves for the support of the
carrier frame 7 for the abrading device. The carrier frame 7
includes an oil pump 9 which is connected to an oil container 8,
and a hydraulic cylinder-and-piston unit 10 that is connected
thereto, which is coupled at its free end with a sled 11a which is
shiftably guided in a vertical sliding guide 11.
A bearing bracket 6 is affixed to the vertically movable sled
11a.
The bearing bracket 6 serves, on the one hand, for the
accommodation and bearing of the driving shaft 13 which is
configurated as a hollow shaft and, on the other hand, for the
accommodation of a steplessly controllable compressed air motor 12
the pinion 35 of which directly meshes with a gear ring 34 at the
upper end of the driving shaft 13.
At the lower end of the driving shaft 13 which is, in this manner,
guided centrally within the melting vessel 1 in direction of the
arrows Z for vertical shifting, there is provided a flange 17 which
serves for the connection of a rotary cross serving as rotary body.
The four arms 15 of the rotary cross are connected at the outer
periphery by means of a profiled ring 16. At the outer periphery of
the profiled ring, there are respectively connected in the region
of the arms 15, pairs of chains 18 and 19 at the free ends of which
the abrasion tools 20 are provided. The chains 18 and 19 are
configurated as side-bar chains, link chain or roller chains so
that the abrasion tools 20 which are affixed to their ends are to a
certain limit radially as well as tangentially yieldable or movable
in the radial plane of the rotary body 15, 16.
As is evident from FIG. 1, the chains 18 and 19 have such lengths
that the radial attack region of the abrading tools, when they are
fully extended radially under the influence of the centrifugal
force, is limited to the radial depth of that marginal layer which
is still penetrated or infiltrated by metal or metallic oxides an
thus is to be abraded.
The abrading tools 20 consist of substantially prismatic, edged
steel blocks with a rectangular or square cross section.
In order to be able to fit this embodiment to different inner
diameters of the vessel, it is possible to make the arms 15 of the
rotary cross adjustable in length, for instance telescopically.
Instead, merely the chains 18 and 19 can be exchanged for
correspondingly shorter or longer chains.
The embodiment of the eroding arrangement according to FIGS. 2, 3
and 4 differs from the previously described substantially by the
changed configuration of the rotary body.
This embodiment consists of two circular steel plates or disks 21
and 22, between which carrier arms 24 are supported by means of
bearing sleeves 23 for pivoting in the radial plane. In the
illustrated embodiment, five of such carrier arms are arranged in
this manner, being distributed over the periphery at uniform
spacings. At the free ends of the carrier arms, which are angled or
curved against the direction of rotation Y, there are again affixed
by means of the chain pairs 18, 19 the abrading tools 20.
This pivotable mounting of the carrier arms 24 in the radial plane
of the rotary body 21, 22 serves the purpose of fitting the radial
range of attack of the slag abrading device to vessels with a
different inner diameter. For this purpose, the bearing sleeves 23
of the carrier arms 24 are provided with sprocket wheels 29, which
are commonly engaged by an endless gear chain 30. In order to
maintain the chain 30 at a sufficient tension, there is provided an
adjustable or spring-biased tensioning roller or toothed wheel 30a
(compare FIG. 2).
As may especially be ascertained from FIG. 4, the hollow driving
shaft 13 has an adjustment linkage 25 passing therethrough, which
at its lower end carries a toothed wheel 26. The wheel 26 is
coupled via a further endless chain 27 for rotation with the
toothed wheel 28 at the opposite lower end of one of the bearing
sleeves 23 for the carrier arms 24. At the upper end which extends
beyond the hollow driving shaft, the adjusting linkage 25 is
provided with a tilting lever 31 which is arrestable in the
respective tilting positions by means of abutments 33. In this
manner, the arrested position of the carrier arms 24 can be varied
to fit different inner diameters of the vessel.
As appears from FIG. 4, the arresting abutment or abutments 33 for
the tilting lever 31 are affixed to the upper side of a
flange-shaped covering plate 32 which rotates with the driving
shaft 13, and by means of which the driving shaft 13 possibly bears
on an axial roller bearing, and underneath which the toothed ring
24 for the rotary drive of the driving shaft by means of the
compressed air motor is arranged.
The above-described abrading device has been sucessfully employed,
for testing purposes, in a melting vessel having an inner diameter
of approximately 1 m and at a temperature of the lining of
approximately 800.degree. C. Herein, steel blocks having a weight
of 16 kg each have been used as abrading tools. In this
arrangement, the rotary body which has been provided with the
abrading tools has been brought, by means of the driving shaft,
into the vicinity of the vessel bottom and, thereafter, set into
rotational movement by activating the compressed air motor. The
originally low orbiting speed was then gradually increased upto a
value of approximately 5.3 m/sec. After that, the arrangement has
been raised, at a speed of approximately 160 mm/sec, commencing at
the vessel bottom, and removed from the melting vessel again after
a single stroke. The inner surface of the vessel lining, on which
before the treatment slag incrustations having a thickness of 100
mm and more adhered, was thereafter centrical as well as fully
smooth and free of any incrustations and inner marginal portions
infiltrated by metal or metallic oxides. In a vessel having an
inner height of 1.2 m, the whole operation lasted a surprisingly
short time of approximately 11 minutes only.
The special advantage of the arrangement of the invention resides,
moreover, in the fact that it requires only a relatively modest
expenditure in the construction of the apparatus, is simple and
rugged and can be easily fitted to different diameters of the
treated vessel. In the event of wear of the abrasion tools their
replacement takes place without incurring any labor and time
expenses worth mentioning.
In order to be able to fit the arrangement to different inner
diameters of the vessel with respect to the centrical arrangement
of the driving shaft 13 or of the rotary body, the carrier frame 7
can be radially shiftable on a guiding plate of the metallic
support frame 5 and arrestable, for example, by means of plug-in
holes and plug pins 36, 36a, in the desired radial position.
* * * * *